Hyper-IgG4 disease: report and characterisation of a new disease

IgG4-related sclerosing disease involving the superior vena cava and the atrial septum of the heart

A 55-year-old woman presented with frequent episodes of syncope due to sinus pauses. During ambulatory Holter monitoring, atrial fibrillation and first-degree atrioventricular nodal block were observed. Magnetic resonance imaging and CT scans showed a tumor-like mass from the superior vena cava to the right atrial septum. Open chest cardiac biopsy was performed. The tumor was composed of proliferating IgG4-positive plasma cells and lymphocytes with surrounding sclerosis. The patient was diagnosed with IgG4-related sclerosing disease. Because of frequent sinus pauses and syncope, a permanent pacemaker was implanted. The cardiac mass was inoperable, but it did not progress during the one-year follow-up.

Comparison between sarcoidosis and IgG4-related disease by whole-body 67Ga scintigraphy

PURPOSE

The aim of this study was to compare uptake lesions in sarcoidosis and IgG4-related disease through gallium-67 ((67)Ga) scintigraphy to differentiate between the two diseases.

MATERIALS AND METHODS

Whole-body (67)Ga scintigraphy findings of 27 patients with sarcoidosis and 16 with IgG4-related disease were reviewed between 2005 and 2011 at our hospital.

RESULTS

In the case of patients with sarcoidosis, significant accumulation of (67)Ga was observed in the lacrimal gland in the case of 26 patients (96%), in mediastinal lymph nodes (LNs) in 23 (85%), in pulmonary hilar LNs in 21 (78%), in the parotid gland in 10 (38%), in supraclavicular LNs in eight (30%), in muscles in seven (26%), in the lung in five (18%), in inguinal LNs in four (15%), in submandibular LNs in two (7%), and in the heart, spleen, kidney and para-aorta in one patient (4%). In patients with IgG4-related disease, abnormal uptake was detected in the pulmonary hilar LNs in 12 patients (75%), in the lacrimal gland in 10 (62%), in the pancreas in 10 (62%), in the parotid gland in six (37%), in the submandibular gland in six (37%), in the para-aorta in three (19%), in the lung in three (19%), in mediastinal LNs in two (12%), and in the kidney in the case of two patients (12%). Asymmetrical accumulation in the submandibular gland was observed in three of six patients (50%) with IgG4-related disease and in none of the two patients (0%) with sarcoidosis. Significant differences were observed in the uptake ratio of the lacrimal gland, the submandibular gland, supraclavicular LNs, mediastinal LNs, pancreas, and muscle between the two groups (P<0.05).

CONCLUSION

(67)Ga scintigraphy was useful in differentiating between the two diseases. Uptake in mediastinal LNs, in supraclavicular LNs, and in the muscle was specific to sarcoidosis, whereas uptake in the pancreas and in the submandibular gland indicated IgG4-related disease.

Spontaneous remission in a case of idiopathic retroperitoneal fibrosis

A 54-year-old lady being investigated at the medical clinic for back pain and weight loss, was diagnosed with idiopathic retroperitoneal fibrosis on the basis of CT imaging, biopsy findings and absence of known secondary causes. After lengthy discussions with the patient during several clinic visits she declined the use of corticosteroid treatment due to concerns for the potential side effects. Serial monitoring of inflammatory markers and interval imaging suggested a spontaneous remission in the inflammatory process. We describe the case and discuss the management of retroperitoneal fibrosis.

IgG4 subclass antibodies impair antitumor immunity in melanoma

Host-induced antibodies and their contributions to cancer inflammation are largely unexplored. IgG4 subclass antibodies are present in IL-10-driven Th2 immune responses in some inflammatory conditions. Since Th2-biased inflammation is a hallmark of tumor microenvironments, we investigated the presence and functional implications of IgG4 in malignant melanoma. Consistent with Th2 inflammation, CD22+ B cells and IgG4(+)-infiltrating cells accumulated in tumors, and IL-10, IL-4, and tumor-reactive IgG4 were expressed in situ. When compared with B cells from patient lymph nodes and blood, tumor-associated B cells were polarized to produce IgG4. Secreted B cells increased VEGF and IgG4, and tumor cells enhanced IL-10 secretion in cocultures. Unlike IgG1, an engineered tumor antigen-specific IgG4 was ineffective in triggering effector cell-mediated tumor killing in vitro. Antigen-specific and nonspecific IgG4 inhibited IgG1-mediated tumoricidal functions. IgG4 blockade was mediated through reduction of FcγRI activation. Additionally, IgG4 significantly impaired the potency of tumoricidal IgG1 in a human melanoma xenograft mouse model. Furthermore, serum IgG4 was inversely correlated with patient survival. These findings suggest that IgG4 promoted by tumor-induced Th2-biased inflammation may restrict effector cell functions against tumors, providing a previously unexplored aspect of tumor-induced immune escape and a basis for biomarker development and patient-specific therapeutic approaches.

Retroperitoneal fibrosis

Retroperitoneal fibrosis is a rare syndrome hallmarked by a fibrosclerotic tissue in the retroperitoneum, often leading to encasement of the ureters. About two-thirds of cases of retroperitoneal fibrosis are idiopathic, while the remaining cases are secondary to a variety of different causes, including drugs, tumors and infections. Idiopathic retroperitoneal fibrosis may be associated with abdominal aorta aneurysms, with vasculitis of the thoracic aorta and of epi-aortic vessels, or both. Most patients present with abdominal and/or low back pain. Serum markers of inflammation are usually, but not invariably, elevated. The diagnosis is secured by computed tomography or magnetic resonance imaging, which typically show an enhancing retroperitoneal mass medially dislodging the ureters. Positron emission tomography can be useful to document the extent and metabolic activity of the inflammatory process. Treatment rests on glucocorticoids with a tapering scheme variably combined with immunosuppressive agents. In cases of ureter obstruction, relief of obstruction by stenting or ureterolysis is required.

A case of intraperitoneal immunoglobulin G4-related inflammatory pseudotumor

The term inflammatory pseudotumor (IPT) has been used to describe inflammatory and fibrosing tumoral processes of an undetermined cause that may involve a variety of organ system. IgG4-related disease is a newly recognized fibroinflammatory condition characterized by IgG4-producing plasma cell expansion in affected organs and, often but not always, elevated serum IgG4 concentrations. IgG4-related IPTs, a subtype of IPT, are characterized by dense infiltration of IgG4-positive plasma cells and stromal fibrosis. The association between inflammatory pseudotumor and IgG4 was first reported with a regard to sclerosing pancreatitis. Despite there are many reports on intraperitoneal IPTs including both cellular and lymphoplasmacytic type, only a few cases have been confirmed to be IgG4-related. We experienced a case of intraperitoneal IgG4-related inflammatory pseudotumor in an 83-year-old woman presenting with epigastric pain and malaise. Surgical specimens revealed an IgG4-related inflammatory pseudotumor.

Immunoglobulin g4-related systemic sclerosing disease: a case involving the ureter and kidney

Immunoglobulin (Ig) G4-related sclerosing disease is a newly defined clinicopathological entity characterized by lymphoplasmacytic infiltration of IgG4-positive plasma cells and varying degrees of fibrosis within affected tissues. Patients usually exhibit multisystem involvement and often respond well to steroid and immunosuppressive therapy. This report presents a case of IgG4-related sclerosing disease involving the ureter and kidney. We hope to bring IgG4-related sclerosing disease to the attention of urologists, because it is an uncommon disease that commonly responds to systemic corticosteroids.

Rethinking Ormond's disease: "idiopathic" retroperitoneal fibrosis in the era of IgG4-related disease

Idiopathic retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent retroperitoneal structures, particularly the ureters. A subset of idiopathic RPF cases can be associated with IgG4-related disease, but the frequency of this association is not clear. We selected 23 cases of idiopathic RPF and identified IgG4-related RPF cases based on the presence of IgG4+ plasma cells in the tissue, using an IgG4/IgG ratio cutoff of >40%. We then compared the IgG4-related RPF patients and the non-IgG4-related RPF patients in terms of both the presence of histopathologic features typical of IgG4-related disease and the simultaneous occurrence (or history) of other organ manifestations typical of IgG4-related disease. The IgG4-related RPF and non-IgG4-related RPF groups were also analyzed in terms of clinical, laboratory, and radiologic features and treatment review. We identified 13 cases of IgG4-related RPF (57% of the total cohort). The distinguishing features of IgG4-related RPF were histopathologic and extra-organ manifestations of IgG4-related disease. The IgG4-related RPF patients were statistically more likely than non-IgG4-related RPF patients to have retroperitoneal biopsies showing lymphoplasmacytic infiltrate (p = 0.006), storiform fibrosis (p = 0.006), or tissue eosinophilia (p = 0.0002). Demographics of the 2 groups, including a middle-aged, male predominance (mean age, 58 yr; 73% male), were similar. IgG4-related disease accounts for a substantial percentage of patients with "idiopathic" RPF. Histopathologic features such as storiform fibrosis, obliterative phlebitis, and tissue eosinophilia are critical to identifying this disease association. Extraretroperitoneal manifestations of IgG4-related disease are also often present among patients with IgG4-related RPF. Elevated IgG4/total IgG ratios in tissue biopsies are more useful than the number of IgG4+ plasma cells per high-power field in cases of RPF that are highly fibrotic.

Immunoglobulin G4-positive Sclerosing Idiopathic Orbital Inflammation: New Neuro-ophthalmological Presentations

We report two rare cases of biopsy proven Immunoglobulin G4-related sclerosing orbital inflammation (IgG4SOI). The first case had intracranial involvement which, to our knowledge, is the first IgG4SOI case with serum cerebrospinal fluid abnormalities and the second case had an unusual presentation of a compressive optic neuropathy and systemic lymphadenopathy.

Retroperitoneal fibrosis associated with immunoglobulin G4-related disease

Retroperitoneal fibrosis is a rare disease characterized by the development of inflammation and fibrosis in the soft tissues of the retroperitoneum and other abdominal organs. Retroperitoneal fibrosis can be of 2 types: idiopathic and secondary. The recently advocated concept and diagnostic criteria of immunoglobulin G4 (IgG4)-related disease, derived from research on autoimmune pancreatitis (AIP), has led to widespread recognition of retroperitoneal fibrosis as a condition caused by IgG4-related disease. We now know that previously diagnosed idiopathic retroperitoneal fibrosis includes IgG4-related disease; however, the actual prevalence is unclear. Conversely, some reports on AIP suggest that retroperitoneal fibrosis is concurrently found in about 10% of IgG4-related disease. Because retroperitoneal fibrosis has no specific symptoms, diagnosis is primarily based on diagnostic imaging (computed tomography and magnetic resonance imaging), which is also useful in evaluating the effect of therapy. Idiopathic retroperitoneal fibrosis can occur at different times with other lesions of IgG4-related disease including AIP. Thus, the IgG4 assay is recommended to diagnose idiopathic retroperitoneal fibrosis. High serum IgG4 levels should be treated and monitored as a symptom of IgG4-related disease. The first line of treatment for retroperitoneal fibrosis is steroid therapy regardless of its cause. For patients with concurrent AIP, i.e., IgG4-related retroperitoneal fibrosis, the starting dose of steroid is usually 30-40 mg/d. The response to steroid therapy is generally favorable. In most cases, the pancreatic lesion and retroperitoneal fibrosis improve after the initial treatment. However, the epidemiology, treatment for recurring retroperitoneal fibrosis, and long-term prognosis are still largely unknown. Further analysis of such cases and research are necessary.

Autoimmune pancreatitis mimicking pancreatic tumor

Autoimmune pancreatitis (AIP) is a rare disease of unknown pathomechanism. It belongs to the IgG4-related disease family and responds well to steroids, although the relapse rate can reach up to 20–30%. Differentiating AIP from the more common pancreatic cancer can be very challenging. About 20% of AIP is diagnosed postoperatively during final histological examination. Each of the investigative tools can add something to the definitive diagnosis; the question remains whether it is possible to prevent an unnecessary resection. Through our case we would like to demonstrate the differential diagnostic opportunities and present the literary background of this issue. In conclusion, we can state that whenever a focal pancreatic lesion is encountered AIP should always be considered.

A case of IgG4-related retroperitoneal fibrosis mimicking renal pelvic cancer

IgG4-related sclerosing disease is a novel clinicopathological entity characterized by fibrosis, extensive infiltration of IgG4-positive plasma cells, and serum IgG4 elevation. This disorder includes a variety of diseases, such as autoimmune pancreatitis, retroperitoneal fibrosis, sialadenitis, thyroiditis, inflammatory abdominal aneurysm, tubulointerstitial nephritis, and inflammatory pseudotumor [World J Gastroenterol 2008;14:3948-3955]. A 71-year-old man visited our hospital with the complaint of left flank pain and gross hematuria. Computed tomography (CT) revealed left hydronephrosis and a thick retroperitoneal soft tissue mass around the ureteropelvic junction, suspicious of renal pelvic cancer. Urine cytology using a urine sample from the left renal pelvis was negative. On laboratory examination, serum levels of IgG and IgG4 were found to be elevated. The patient refused tumor biopsy. Therefore, he was treated with corticosteroid therapy on the basis of a clinical diagnosis with IgG4-related retroperitoneal fibrosis. Regression of the retroperitoneal mass as well as improvement of left hydronephrosis and decrease in serum IgG4 levels were accomplished. These effects strongly suggested that the present case was an IgG4-related retroperitoneal fibrosis. However, in this instance, since we could not completely rule out malignancies by biopsy, careful follow-up was necessary with these points in mind.

Fibroblastic and myofibroblastic tumors in children and adolescents

Fibroblastic and myofibroblastic tumors in children and adolescents are a relatively common group of soft tissue proliferations that range from reactive to hamartomatous to neoplastic, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic and immunohistochemical overlap, despite significant clinical, genetic, and prognostic differences. The fibromatoses are a major subgroup, and all types of fibromatoses can occur in the 1st 2 decades of life. Intermediate and malignant fibroblastic-myofibroblastic tumors are an important group that includes variants of fibrosarcoma and other tumors with recurrent cytogenetic or molecular genetic abnormalities and low metastatic potential. Pathologic examination is enhanced by adjunct techniques, such as immunohistochemistry, cytogenetics, and molecular genetics, although morphology provides the ultimate criteria for a specific diagnosis. This article reviews the clinicopathologic features of fibroblastic and myofibroblastic tumors with an emphasis on the unique aspects of these neoplasms in children and adolescents, the use of diagnostic adjuncts, and differential diagnoses.

Are Classification Criteria for IgG4-RD Now Possible? The Concept of IgG4-Related Disease and Proposal of Comprehensive Diagnostic Criteria in Japan

Recent studies suggest simultaneous or metachronous lesions in multiorgans characterized by elevated serum levels of IgG4 and abundant infiltration of IgG4-positive plasma cells with various degrees of fibrosis. Two Japanese research committees for IgG4-RD, one from fibrosclerosis (Okazaki team) and the other from lymph proliferation (Umehara team) supported by the “Research Program for Intractable Disease” of the Ministry of Health, Labor, and Welfare of Japan, have agreed with the unified nomenclature as “IgG4-RD” and proposed the comprehensive diagnostic criteria (CDC) for IgG4-RD. Validation of the CDC demonstrated satisfactory sensitivity for the practical use of general physicians and nonspecialists but low sensitivity in the organs to be difficult in taking biopsy specimens such as type1 autoimmune pancreatitis (IgG4-related AIP), compared with IgG4-related sialadenitis/dacryoadenitis (Mikulicz's disease) and IgG4-related kidney disease. Although the diagnostic criteria covering all IgG4-RD are hard to be established, combination with the CDC and organ-specific diagnostic criteria should improve sensitivity.

CCL18 -- potential biomarker of fibroinflammatory activity in chronic periaortitis

OBJECTIVE

Promising therapeutic approaches have emerged in chronic periaortitis, whereas peripheral blood biomarkers are lacking. CC-chemokine ligand 18 (CCL18) is known as a marker of fibrotic activity and prognosis in pulmonary fibrosis. We investigated whether CCL18 levels are increased in patients with chronic periaortitis and are associated with clinical, laboratory, and imaging findings.

METHODS

In this retrospective study, serum concentrations of CCL18 were assessed in 30 patients with chronic periaortitis and related to clinical data, laboratory variables, and imaging studies. Serum levels were compared to 15 apparently healthy volunteers and 15 controls with aortic sclerosis.

RESULTS

Serum concentrations of CCL18 were increased in patients with chronic periaortitis (median 197.6 ng/ml, range 73.7-301.0) compared to healthy volunteers (median 34.6 ng/ml, range 22.6-70.4; p < 0.0001) and controls with aortic sclerosis (median 50.4 ng/ml, range 24.5-141.2; p < 0.0001). CCL18 levels correlated with (n = 30; r = 0.461, p = 0.01) and increased with the transversal diameter of the periaortic mantle < 5, 5-10, and ≥ 10 mm (p = 0.008). Contrast enhancement (p = 0.044), treatment naivety (p = 0.042), and the occurrence of systemic symptoms (p = 0.007) were associated with higher CCL18 levels. During followup, changes of CCL18 correlated with changes of the transverse diameter of the periaortic mantle (n = 17; r = 0.512, p = 0.033).

CONCLUSION

Serum concentration of CCL18 reflects fibroinflammatory activity and extent of disease in patients with chronic periaortitis.

[IgG4-related disease and renal and urological involvement]

Hyper-IgG4 syndrome, or IgG4-related disease, is an emerging disorder, involving one or more organ(s), and characterized by "storiform" fibrosis and inflammatory lesions with a predominance of IgG4+ plasma cells and increased IgG4 serum levels. Since the first report of auto-immune pancreatitis, numerous organ lesions have been reported and have been found to occur in a same patient including: sialadenitis, dacryoadenitis, lymphadenopathy, liver and biliary tract involvement, and renal and retroperitoneal lesions. Renal involvement was first described in 2004 and usually presents as functional and/or morphological abnormalities. In most cases, renal pathological analysis reveals tubulointerstitial nephritis that is rarely associated with glomerular lesions. Retroperitoneal fibrosis is also a typical feature that may be associated with periaortitis or inflammatory abdominal aortic aneurysm. First line treatment is based on corticosteroid therapy. Short-term outcome is usually favorable. However, patients should be carefully monitored for relapses and long-term complications. Although the multiple organ lesions share common clinical, biological, radiological and pathological features, no consensus diagnostic criteria have yet been validated for IgG4-related disease. Ruling out differential diagnoses is thus mandatory. Our literature review provides nephrologists, urologists and pathologists with key elements that will help in the early diagnosis and proper management of this new and emerging disorder.

[¹⁸F]FDG-PET/CT in patients affected by retroperitoneal fibrosis: a bicentric experience

PURPOSE

The aim of our study was to assess the feasibility and usefulness of 2-[(18)F]-fluoro-2-deoxy-D: -glucose positron emission tomography computed tomography ([(18)F]FDG-PET/CT) in patients affected by retroperitoneal fibrosis.

MATERIALS AND METHODS

We retrospectively evaluated 25 patients studied in two centers: 18 underwent [(18)F]FDG-PET/CT as initial evaluation, three during follow-up, three during steroid therapy, and one to re-evaluate the disease. Among the group who underwent initial evaluation, ten underwent a second [(18)F]FDG-PET/CT after steroid therapy.

RESULTS

[(18)F]FDG-PET/CT was positive in 18 patients and negative in seven. Among the ten patients who underwent a second study after steroid therapy, six showed complete metabolic response, three partial response, and one no significant maximum standardized uptake value (SUV(max)) reduction.

CONCLUSION

Our preliminary results show that [(18)F]FDG-PET/CT is feasible and suitable for evaluating retroperitoneal fibrosis and is useful in assessing therapy response. Larger studies are desirable to confirm these findings and to determine the appropriate position of [(18)F]FDG-PET/CT in the diagnostic flow chart for this disease.

IgG4-related sclerosing disease, an emerging entity: a review of a multi-system disease

Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. Steroid therapy comprises the mainstay of treatment. Disease progression with involvement of multiple organ-sites may be encountered in a subset of cases and may follow a relapsing-remitting course. The principal histopathologic findings in several extranodal sites include lymphoplasmacytic infiltration, lymphoid follicle formation, sclerosis and obliterative phlebitis, along with atrophy and destruction of tissues. Immunohistochemical staining shows increased IgG4+ cells in the involved tissues (>50 per high-power field, with IgG4/IgG ratio >40%). IgG4-RSD may potentially be rarely associated with the development of lymphoma and carcinoma. However, the nature and pathogenesis of IgG4-RSD are yet to be fully elucidated and provide immense scope for further studies.

IgG4-related systemic disease--a rare indication for multi-visceral transplantation

Multivisceral transplantations (MVT) are rarely performed procedures. In this case report, we present a 37-year-old male patient with a large retroperitoneal tumor. After exclusion of malignancy, we performed MVT (distal stomach, liver, pancreas, and small bowel). After a follow-up of 1 year, the patient is in good clinical condition. Histologic examination revealed a chronic sclerosing IgG4-associated disease. Our case shows that MVT can be successfully performed in this rare disease.

Multifocal fibrosclerosis and IgG4-related disease involving the cardiovascular system

The cardiovascular system may be involved as a target organ of multifocal fibrosclerosis, which may manifest as idiopathic retroperitoneal fibrosis, inflammatory aortic aneurysm, inflammatory periarteritis, and inflammatory pericarditis. These pathological conditions can sometimes occur concomitantly. Idiopathic retroperitoneal fibrosis and inflammatory abdominal aortic aneurysm are both characterized by the presence of fibro-inflammatory tissue around the abdominal aorta expanding into the surrounding retroperitoneal structures, and together they may be termed 'chronic periaortitis'. Cardiovascular fibrosclerosis has become non-uncommonly encountered condition since imaging modalities have made its diagnosis more feasible. In addition, recent studies have demonstrated that a certain fraction, but not all, of cardiovascular fibrosclerosis may have a link with immunoglobulin-G4 (IgG4)-related sclerosing disease (IgG4-SD). IgG4-SD is histologically characterized by dense fibrosclerosis and infiltration of lymphocytes and IgG4-positive plasma cells, and these histopathologic findings seem to be essentially similar regardless of the organs involved. In this mini review, we summarize what is known so far about multifocal fibrosclerosis of the cardiovascular system and its association with IgG4-SD, and what remains to be clarified in future investigations.

[IgG4-related systemic disease: emergence of a new systemic disease? Literature review]

Hyper-IgG4 syndrome, or IgG4-related systemic disease (IgG4-RSD), has been recently characterized by the association of a focal or diffuse enlargement in one or more organs, elevated levels of serum IgG4 and histopathological findings including "storiform" fibrosis and prominent infiltration of lymphocytes and IgG4-positive plasma cells. Pancreas was the first organ involved with sclerosing pancreatitis (or autoimmune pancreatitis). Since this first description, many extrapancreatic lesions have been described, even in the absence of pancreatitis and include sialadenitis, lacrimal gland inflammation, lymphadenopathy, aortitis, sclerosing cholangitis, tubulointerstitial nephritis, retroperitoneal fibrosis or inflammatory pseudotumors. Multiorgan lesions can occur synchronously or metachronously in a same patient, usually after 50 years of age. They all share common histopathological findings. The disease often responds well to corticosteroid therapy. In this literature review on IgG4-RSD, we present historical, epidemiological and clinical characteristics, and we review the biological and histological diagnostic criteria. To date there is no international validated diagnostic criteria. Pathophysiological hypothesis and therapeutic approaches are also discussed.

Whole-body gallium-67 scintigraphic findings in IgG4-related disease

PURPOSE

To clarify the features of gallium-67 (Ga-67) imaging typical of IgG4-related disease.

METHODS

We retrospectively investigated 14 patients diagnosed with IgG4-related disease who underwent Ga-67 scintigraphy in our hospital between January 2005 and May 2010. Of these, 13 patients who underwent gallium scintigraphy before steroid therapy were enrolled in this study. The patient population comprised 11 men and 2 women with age ranging from 47 to 76 years (mean age, 61.9 years).

RESULTS

Among the 13 patients, significant accumulation of Ga-67 was detected in the bilateral pulmonary hila in 10 patients (77%), pancreas in 10 (77%), salivary glands in 7 (54%), lacrimal glands in 7 (54%), periaortic lesions in 2 (15%), and lung parenchyma in 1 (8%) patient. High accumulation of Ga-67 in the salivary glands was observed in the parotid glands in 3 cases and in the submandibular glands in 6 cases, with the following pattern: normal parotid gland uptake and symmetrical submandibular gland uptake in 2 cases; symmetrical high accumulation in both parotid and submandibular glands in 1 case; symmetrical high accumulation in parotid glands and normal submandibular gland uptake in 1 case; symmetrical uptake by parotid glands and asymmetric uptake by submandibular glands in 1 case; normal parotid gland uptake and asymmetric submandibular gland uptake in 1 case; and asymmetric parotid gland uptake and symmetrical parotid gland uptake in 1 case.

CONCLUSION

Characteristic patterns of gallium uptake would be helpful for diagnosis, detection of involved lesions, and differential diagnosis in patients with IgG4-related disease to avoid unnecessary surgery.

Suspected idiopathic sclerosing orbital inflammation presenting as immunoglobulin G4-related disease: a case report

INTRODUCTION

Idiopathic sclerosing orbital inflammation is a rare and ill-defined heterogeneous entity, and a distinct subset of orbital inflammation. Recently, attention has been focused on immunoglobulin G4-related disease complicated with fibrotic changes in some other organs with high serum immunoglobulin G4 levels. This report presents a case of suspected idiopathic sclerosing orbital inflammation complicated with high serum immunoglobulin G4 levels.

CASE PRESENTATION

An 82-year-old Japanese woman had a 30-year history of chronic thyroiditis. She experienced right ptosis and eyelid swelling. These symptoms gradually developed over five years. The clinical and radiographic findings suggested that our patient had idiopathic sclerosing orbital inflammation. We were unable to obtain our patient's consent to perform a biopsy. While the serum immunoglobulin G level was within the normal limits, the serum immunoglobulin G4 level was significantly elevated. The serum immunoglobulin G4 levels decreased after the administration of oral prednisolone at a daily dose of 20 mg. In addition, the swelling and ptosis of the right upper eyelid disappeared gradually after four weeks. Our patient was then suspected to have idiopathic sclerosing orbital inflammation complicated with immunoglobulin G4-related disease and chronic thyroiditis.

CONCLUSION

An orbital pseudotumor of this type is indicative of idiopathic sclerosing orbital inflammation immunoglobulin G4-related disease. Immunoglobulin G4 may thus be considered a subclass of immunoglobulin G when the serum immunoglobulin G level is within normal limits.

A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details

IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz’s disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity.

Role of endothelial-mesenchymal transition (EndoMT) in the pathogenesis of fibrotic disorders

The accumulation of a large number of myofibroblasts is responsible for exaggerated and uncontrolled production of extracellular matrix during the development and progression of pathological fibrosis. Myofibroblasts in fibrotic tissues are derived from at least three sources: expansion and activation of resident tissue fibroblasts, transition of epithelial cells into mesenchymal cells (epithelial-mesenchymal transition, EMT), and tissue migration of bone marrow-derived circulating fibrocytes. Recently, endothelial to mesenchymal transition (EndoMT), a newly recognized type of cellular transdifferentiation, has emerged as another possible source of tissue myofibroblasts. EndoMT is a complex biological process in which endothelial cells lose their specific markers and acquire a mesenchymal or myofibroblastic phenotype and express mesenchymal cell products such as α smooth muscle actin (α-SMA) and type I collagen. Similar to EMT, EndoMT can be induced by transforming growth factor (TGF-β). Recent studies using cell-lineage analysis have demonstrated that EndoMT may be an important mechanism in the pathogenesis of pulmonary, cardiac, and kidney fibrosis, and may represent a novel therapeutic target for fibrotic disorders.

Association of HLA and post-schistosomal hepatic disorder: a systematic review and meta-analysis

Several human genetic variants, HLA antigens and alleles are reportedly linked to post-schistosomal hepatic disorder (PSHD), but the results from these reports are highly inconclusive. In order to estimate overall associations between human genetic variants, HLA antigens, HLA alleles and PSHD, we systematically reviewed and performed a meta-analysis of relevant studies in both post-schistosomal hepatic disorder and post-schistosomal non-hepatic disorder patients. PubMed, Scopus, Google Scholar, The HuGE Published Literature database, Cochrane Library, and manual search of reference lists of articles published before July 2009 were used to retrieve relevant studies. Two reviewers independently selected articles and extracted data on study characteristics and data regarding the association between genetic variants, HLA antigens, HLA alleles and PSHD in the form of 2×2 tables. A meta-analysis using fixed-effects or random-effects models to pooled odds ratios (OR) with corresponding 95% confidence intervals were calculated only if more than one study had investigated particular variation. We found 17 articles that met our eligibility criteria. Schistosoma mansoni and Schistosoma japonicum were reported as the species causing PSHD. Since human genetic variants were only investigated in one study, these markers were not assessed by meta-analysis. Thus, only HLA-genes (a total of 66 HLA markers) were conducted in the meta-analysis. Our meta-analysis showed that human leucocyte antigens HLA-DQB1*0201 (OR=2.64, P=0.018), DQB1*0303 (OR=1.93, P=0.008), and DRB1*0901 (OR=2.14, P=0.002) alleles and HLA-A1 (OR=5.10, P=0.001), A2 (OR=2.17, P=0.005), B5 (OR=4.63, P=0.001), B8 (OR=2.99, P=0.02), and B12 (OR=5.49, P=0.005) serotypes enhanced susceptibility to PSHD, whereas HLA-DQA1*0501 (OR=0.29, P≤0.001) and DQB1*0301 (OR=0.58, P=0.007) were protective factors against the disease. We further suggested that the DRB1*0901-DQB1*0201, DRB1*0901-DQB1*0303 and A1-B8 haplotypes enhanced susceptibility to PSHD, whereas DQA1*0501-DQB1*0301 linkage decreased the risk of PSHD. The result improved our understanding of the association between the HLA loci and PSHD with regard to pathogenic or protective T-cells and provided novel evidence that HLA alleles may influence disease severity.

A clinical overview of IgG4-related systemic disease

PURPOSE OF REVIEW

To summarize the existing knowledge of various clinical presentations of IgG4-related systemic disease (IgG4-RSD) and to review the evolving list of organs affected by IgG4-RSD.

RECENT FINDINGS

The term IgG4-RSD encompasses a variety of clinical entities once regarded as being entirely separate diseases. The list of organs associated with this condition is growing steadily. Tissue biopsies reveal striking histopathological similarity, regardless of which organ is involved, although subtle differences across organs exist. Diffuse lymphoplasmacytic infiltrates, presence of abundant IgG4-positive plasma cells and extensive fibrosis are the hallmark pathology findings. Tumorous swelling, eosinophilia, and obliterative phlebitis are other frequently observed features. Polyclonal elevations of serum IgG4 are found in most but not all patients.

SUMMARY

IgG4-RSD is an underrecognized condition about which knowledge is now growing rapidly. Yet there remain many unknowns with regard to its cause, pathogenesis, various clinical presentations, approach to treatment, disease monitoring, and long-term outcomes. A wide variety of organs can be involved in IgG4-RSD. Clinicians should be aware of this entity and consider the diagnosis in the appropriate settings.

Immunoglobulin G4 (IgG4)-positive or -negative ocular adnexal benign lymphoid lesions in relation to systemic involvement

The purpose of this study is to determine the relationship of ocular adnexal benign or reactive lymphoid hyperplasia, including orbital pseudotumor, with immunoglobulin G4 (IgG4)-related diseases. Medical charts of 9 consecutive patients with ocular adnexal benign lymphoid lesions, seen in the Department of Ophthalmology, Okayama University Hospital, were reviewed, and pathological sections were restained immunohistochemically for IgG4-, IgG-, and CD138-positive plasma cells. The diagnosis of IgG4-positive lesions was based on 10 or more IgG4-positive plasma cells in a high-power field and greater than 40% ratios of IgG4-positive plasma cells/CD138-positive plasma cells and IgG4-positive plasma cells/IgG-positive plasma cells. IgG4-positive lesions were determined as absent in 5 patients (4 with bilateral lacrimal/orbital lesions and one with a unilateral conjunctival lesion), none of whom showed systemic manifestations. In contrast, IgG4-positive lesions were present in 4 patients (3 with bilateral lacrimal/orbital lesions and one with a unilateral lacrimal/orbital lesion), who showed systemic manifestations : one with Hashimoto thyroiditis, one with IgG4-positive bilateral interstitial lung disease and hepatic inflammatory pseudotumor, one with bilateral interstitial lung disease, and one with systemic lymphadenopathy and antiphospholipid syndrome. In conclusion, IgG4-positive ocular adnexal benign lymphoid lesions might be used as a benchmark for the probable presence of other systemic lymphoid lesions.